Conventionally, large numbers of invoices are required to be generated for customers subscribing to various services and residing in certain geographical territories having required municipal government taxes. Those fees, taxes and other price points are dynamic variables which change over time or over varying locations. Such tax variables are especially difficult to track in countries, such as Brazil and Mexico since the tax rates must be present on the invoices generated by the large phone carrier companies. Also, the tax rates change so often that a phone billing application is required to provide dynamic billing and invoicing for the various customers using those services.